Since most books today cover only what bullets are made by the manufacturer, you may have to look through old loading books. Most "modern" manuals in NAmerica deal with only up to 180gr. in the .303.
My old Lyman books use the normal range of IMR powders of course.

215gr. STARTING loads - 32.0 3031 @ 1,840fps, 35.0 4064 @ 1,698fps, 36.0gr 4895 @ 2,000fps and 37.0gr. 4320 @ 2,008fps.

Your 36.0gr. 4895 and 4064 may be reasonable, but actually seems a bit light, to me, even for an old Lee Speed.

Maximums listed by Lyman are 36.0gr. 3031 @ 2,057fps, 39.0gr. 4064 @ 1,996fps, 40.0gr. 4895 @ 2,217fps and 41.0gr. 4320 @ 2,217fps - all from Lyman #44 (1967)